The invention broadly relates to control valves, and more specifically to a safe fuel gas valve of a type which, after ignition of a standing pilot burner, permits operation only when the pilot flame is present.
U.S. Pat. No. 4,543,974, which issued on Oct. 1, 1985, and is commonly owned with the present patent application, discloses a gas control valve for use with a standing pilot, the valve operating on an on-off basis by an electromagnetic actuator which responds to a conventional electric thermostat. A pilot valve is manually opened to permit a pilot burner to be lit, and an inlet safety valve for the device permits the flow of gas to the pilot valve and main valve only when the pilot flame exists. There is no functional relationship between the safety valve and main valve, and the electromagnetic actuator is capable of opening and closing the main valve whether or not the safety valve is open.
U.S. Pat. No. 3,973,576, which issued on Apr. 10, 1976 and is commonly owned with the present application, discloses a gas valve having a safety valve opened by a mechanism that is actuated only if a pilot flame is established. This feature, which provides "super safe" operation, prevents the valve from being turned off and then back on before it has been safely reset. Such a "super safe" function is a requirement in many European countries.